Abstract : The thesis relates to synthesis and investigation of nanostructured polymer composites based on oligomers of cyanate esters of bisphenol a DCBA or cyclic butylene terephthalate CBT and multiwalled carbon nanotubes MWCNTS. Catalytic effect of mwcnts in process of DCBA polycyclotrimerization as well as in cbt polymerization has been observed. Significant increase in crystallization temperature of nanocomposites based on polybutylene terephthalate cPBT with adding of MWCNTS is observed. The effect of processing method of cpbt-mwcnts nanocomposites on its electrical properties has been found. It has been established that the additional heating of the samples annealing at temperatures above melting of cPBT leads to reagglomeration of MWCNTS in the system. It is established that reagglomeration of MWCNTS results in increase of conductivity values of nanocomposites due to formation of percolation pathways of MWCNTS through polymer matrix. In the case of polycyanurate matrix PCN, it is found that addition of small mwcnts contents 0.03-0.06 weight percents provides increasing tensile strength by 62-94 percents. It has been found that addition of even 0.01 weight percents of MWCNTS provides significant increase in storage modulus of cPBT matrix. This is explained by effective dispersing of small amount of the nanofiller during in situ synthesis of pcn or cpbt matrix that is confirmed by microscopy techniques. It has been established that the properties of the nanocomposites based on heterocyclic esters and MWCNTS can be varied from isolator to conductor and has low percolation thresholds 0.22 and 0.38 weight percents for cPBT and PCN nanocomposites respectively. The conductivity of samples is particularly stable on a very large range of temperature from 300 to 10 degrees Kelvin that make these materials perspective for practical applications in microelectronics, as parts of aircraft and space constructions.